292 franklin: mercury ammonia compounds 



known as hydrated chloride of dimercuriammonium as represented 

 by the formula Hg 2 NCl . H 2 0. The iodide of Millon's base, or 

 Nessler's precipitate, is obtained without the presence of the ele- 

 ments of water and is consequently given the formula Hg 2 NI, 

 which represents it as anhydrous dimercuriammonium iodide. 

 It is shown in the longer paper that Nessler's precipitate is an 

 ammono basic mercuric iodide formed by the ammonolysis of 

 normal mercuric iodide in accordance with the reversible equa- 

 tion 



' 2HgI 2 + 4NH £ <=± Hg : N-Hg-I + 3NH 4 I, 



and that the chloride of Millon's base is a mixed aquo basic am- 

 mono basic salt resulting from the simultaneous hydrolysis and 

 deammonation of the ammonobasic salt NH 2 HgCl as represented 

 by the equation 



2NH 2 -Hg-Cl + H 2 = HO-Hg-NH-Hg-Cl + NH 4 C1 



A very large number of products are described in the literature 

 as having been obtained by the action of aqua ammonia on mer- 

 curic salts. Many of these products are certainly not definite 

 compounds but are basic mixtures which happened to approxi- 

 mate in composition the formulas assigned them. Such as are 

 definite chemical individuals belong to one of the three classes of 

 compounds described above, that is, they are mercuric salts with 

 ammonia of crystallization, ammonobasic salts or aquobasic 

 ammonobasic salts. 



